Folding tablet chair



United States Patent [72] Inventor RaymondC. Barnes Temple, Tex. [21]AppLNo. 737,617 [22] Filed June 17,1968 [45] Patented Dec. 15,1970 [73]Assignee American Desk Manufacturing Company Temple, Tex. a corporationof Texas [54] FOLDINGTABLETCI-IAIR 12 Claims, 15 Drawing Figs.

[52] U.S.Cl. 297/162, 297/154 [51] 1nt.Cl. ..A47b39/00 [50]FleldofSearch 297/162, 155,154,135

[56] References Cited UNITED STATES PATENTS 955,523 4/1910 Lytle 297/1621,731,293 10/1929 Chapman 297/162 3,197,254 7/1965 Hendrickson.. 297/1623,351,377 Ill/I967 Anderson 297/162 3,353,866 11/1967 Chapman 297/162Primary Examiner-James T. McCall Altorney-Baldwin, Wight, Diller & BrownABSTRACT: A chair writing or like tablet is mounted by a compound hingefor movements, about a first axis parallel to the fore-and-aft line ofthe chair and about a second axis transverse to the first axis,selectively to a substantially horizontal position of use, to anelevated intermediate position, and to a lower stowed position alongsidethe chair. Movement of the tablet from its stowed position to itsintermediate position is limited by a stop part having a stop surfaceengageable by a hinge component swingable about the aforesaid secondaxis, thus ensuring that swinging of the tablet from its intermediateposition about the aforesaid first axis to its use" position isaccomplished without interference by engagement of the tablet with thechair arm or other frame part. Means are provided for holding the tabletin a substantially vertical plane when in its stowed position.

PATENTED use! 5 I970 SHEET 1 or a RAYMOND c. BARNES PATENTED DEB? 519msum 2 [1F 4 slsm'ldea PATENTED 05m 5197s saw 3 OF 4 PATENTED 115m SlamSHEET 6 [1? 4 FOLDING TABLET CHAIR This invention relates to foldingtablet chairs, and more particularly to such chairs in which a writingor other work tablet is mounted on the chair frame for swingingmovements selectively to three positions, namely: a use" position inwhich the tablet extends generally or approximately in a horizontalplane above the chair seat, an intermediate position in which the tabletis in a vertical plane at the side of the chair and above its useposition, and a stowed position in which the tablet is in a generallyvertical plane alongside the lower part of the chair.

An object of the invention is to provide a tablet chair of this classincluding a simple, effective and economical compound hinge structuremounting the tablet on the chair frame and enabling such movements andfor limiting the individual movements so as to prevent interference withsubsequent movements to other positions.

Another object of the invention is to provide means for maintaining thetablet in a substantially vertical plane when in its stowed positiondespite any tendency of the tablet to swing gravitationally out of theaforesaid vertical plane.

Other objects of the invention will become apparent from a reading ofthe following more detailed description, the appended claims, and theaccompanying drawings, in which:

FIGS. 1-10 illustrate a construction embodying the invention inconjunction with a portable or movable chair. In these FIGS.:

FIG. 1 is a perspective view of the portable chair, showing a writing orwork surface tablet in position for use;

FIG. 2 is a perspective view showing the tablet in an intermediateposition preparatory to being stowed alongside the chair;

FIG. 3 is a perspective view showing the tablet in stowed position;

FIG. 4 is an exploded perspective view on an enlarged scale showingcompound hinge components in full lines and showing part of the tabletand part of a chair side frame structure in dash lines;

FIG. 5 is a fragmentary side elevational view showing part of the chairframe, tablet and hinge construction, the parts being shown in thepositions corresponding to those shown in FIG. 1, ie the use position,FIG. 5 being on an enlarged scale with respect to FIG. 1 and on areduced scale with respect to FIG. 4;

FIG. 6 is a sectional view on the line 6-6 of FIG. 5, the parts againbeing shown in the use" position; I

FIG. 7 is a fragmentary view on the line 6-6 of FIG. 5, but showing theparts in the intermediate position corresponding to FIG. 2; Y

FIG. 8 is a fragmentary side elevational view similar to FIG. 5, butshowing the parts in the stowed position;

FIG. 9 is a fragmentary sectional view on the line 9-9 of FIG. 8;

vention in conjunction with a floor mounted auditorium or the likechair. In these FIGS.:

FIG. 11 is a fragmentary side elevational view showing the tablet in itsuse" position;

FIG. 12 is a fragmentary front elevational view also showing the tabletin its use" position, this FIG. also showing parts of an adjoining chairin a row of auditorium chairs;

FIG. 13 is a side elevational view showing the tablet in stowedposition;

FIG. 14 is an exploded perspective view showing part of the auditoriumchair frame in dash lines, and showing a compound hinge and the tabletin full lines; and

FIG. 15 is a perspective view of a tablet rest for locating andsupporting the tablet in stowed position, part only of a chair framebeing shown.

The tablet chair structure shown in FIGS. l--l0 includes a chair propercomprising a frame F, a back B and a seat S. The frame includes fourlegs L, a back support BS, a post or vertical arm support member P, asubstantially horizontal chair am A and an arm rest AR.

The upper portion UP of the post P at one side of the frame and abovethe level of the seat S carries a compound hinge CI-I which mounts atablet T for selective movements to a use position extending generallyhorizontally above the chair seat S as shown in FIG. 1, an intermediateposition in a vertical plane and above the post P as shown in FIG. 2,and a stowed position alongside the chair below the chair arm A as shownin FIG. 3. To move the tablet T from its use position shown in FIG. 1 toits intermediate position shown in FIG. 2, the tablet is swung upwardlyabout an axis extending longitudinally of or parallel to thefore-and-aft line of the chair. To move the tablet from its intermediateposition shown in FIG. 2to the stowed position shown in FIG. 3, thetablet is swung substantially in a vertical plane about another axisextending transversely to the axis mentioned above and transversely tothe fore-and-aft line of the chair.

The present invention relates more particularly to the construction andoperation of the compound hinge CH, the parts of which and theircooperative relationship are most clearly illustrated in the enlargedscale FIG. 4. As shown in this FIG. as well as in other FIGS., thecompound hinge Cl-I comprises a hinge stop part element 1 including aflat portion la mounted against the frame upper side portion UP in aplane extending fore-and-aft of the chair, the stop part I beingprovided with locating ears 1b and 10 which project respectively infront of and in contact with the front and rear faces of the frame upperside portion UP. The stop part 1 further includes a stop ear 1d at therear of the part 1 with respect to the chair, the ear Id projecting fromthe flat part 1a oppositely to the ears 1b and 1c. The ear 1d provides afixed forwardly facing stop surface Ie the purpose of which is explainedlater. The stop part flat portion la is also formed with an aperture 1f.

A hinge component 2, mounted adjacent to the hinge stop part I, isformed with downwardly converging front and rear sides 2a and 2b, and apivot aperture 2c through which extends a pintle or pivot screw 3 whichis threaded into a T-nut 4 secured inthe frame part UP, the axis of thescrew 3 being transverse to the fore-and-aft line of the chair. A locknut 5 threaded onto the screw 3 after it has been secured to the T- nut4 holds the screw in such position that its head, two friction washers 6and a metal washer 7 mount the component 2 snugly alongside the flatpart 1a of the stop part 1. The friction washers 6 may be formed, forexample, of laminated phenolic plastic impregnated with graphite, thearrangement being such that the hinge component 2 may pivot about theaxis of the screw 3 which is transverse to the fore-and-aft line of thechair, the pivotal movement, however, being somewhat inhibited orcontrolled by the friction washers 6.

The hinge component 2 mounts another hinge component 8 for swingingabout another axis transverse to the axis of the pintle 3, and thecomponent 8 carries the tablet T. As shown in FIG. 4, the component 8includes a flat, platelike part 8a provided with holes 8b which receivescrews 9 screwed onto the tablet T. A spacer plate 10, for example ofrigid vinyl material, is mounted on the underside of the hinge component8 and is adapted to rest upon the chair arm A when the tablet T is inits use position.

The hinge component 8 further includes mounting ears which fit alongsidethe first mentioned hinge component 2, the ears 80 being provided withholes 8d which receive a pivot pin 1 1 extending through aligned holes2d in the hinge component 2. Snap-on or other suitable retainers 12 holdthe pin 11 in its position extending through the holes 8d and 2d withthe axis of the pin 11 being transverse to the axis of the pivot screw3. The component 2 is recessed at 2e between the holes 2d to accommodatea torsion spring 13 surrounding the pivot pin 11, the purpose of thespring 13 being described hereinafter.

In operation, and assuming firstly that the tablet is in its useposition as shown in FIGS. 1, 4, 5 and 6, the tablet may be moved to itsintermediate position shown in FIGS. 2 and 7 by being swung upwardlycounterclockwise as viewed in FIG. I about the axis of the pivot pin 11while the hinge component 2 remains stationary, although a slightmovement of the component 2 about the axis of the screw 3 during raisingof the tablet T would not be harmful. Movement of the tablet from theintermediate position shown in FIG. 2 to the stowed position shown inFIG. 3 is accomplished by swinging the tablet and the hinge component 2about the axis of the pivot screw 3 until the parts have reached thepositions shown in FIGS. 3, 8, 9 and 10. As shown in FIG. 8, movement ofthe tablet to its stowed position is limited by engagement of the hingecomponent 2 with the lower part of the stop ear 1e. If the tablet isheld somewhat outwardly of the vertical plane when being lowered towardits FIG. 3 stowed position and is then released, it may swing inwardlytoward the chair frame sufficiently to bump the latter and mar the frameor the underside of the tablet T. To prevent any such marring, the postpart P is provided with a cushion bumper CB of rubber or othercushioning material.

With particular reference to FIGS. 9 and 10, it will be seen that whenthe tablet T is lowered alongside the chair to its stowed position, itscenter of gravity will be offset from the axis of the hinge pin 11, andthe tablet will tend to swing under that axis so as to assume aninclined position converging upon the lower part of the chair frame.However, assumption of an inclined position is prevented by the spring13 which is loaded just sufficiently to offset the gravitationaltendency of the tablet to move to the inclined position. The spring 13holds the tablet against that tendency and in a substantially verticalplane extending fore-and-aft of the chair. As shown in FIG. 10, theopposite ends of the spring 13 abut against the inner face of the hingecomponent 2 and the spacer 10, respectively.

To return the tablet T from its stowed or FIG. 3 position to its useposition shown in FIG. 1, the tablet is first swung upwardly about theaxis of the pivot screw 3 to the intermediate positionshown in FIG. 2,overswinging of the tablet in this movement being prevented byengagement of the side 2b of the hinge component 2 with the stop surface1e on the stop ear 1d of the stop part 1. Were it not for this limitingor swinging movement to the intermediate position, it would be possiblefor the movement to be continued to such a degree that it would not thenbe possible to swing the tablet from its intermediate position to itsuse position, because there would be interference with the rear edgeportion of the tablet with the arm rest AR. When the tablet has beenarrested in the proper intermediate position determined by the stopmeans 2b, Ie, the tablet may be swung freely clockwise from its FIG. 2intermediate position to its FIG. 1 use position in which the spacer 10rests upon the arm A and positions the tablet in its predeterminedcorrect working position.

Referring now to the modified arrangement shown in FIGS. 1 l inconjunction with a floor mounted auditorium chair, this construction issimilar in many respects to the construction described above withreference to FIGS. 1--l0, only some parts being modified to adapt thehinge construction to the different basic chair construction. In FIGS.11-15, parts which are essentially the same as parts shown in FIGS. 1-10and have similar functions are designated by the same referencecharacters as their counterparts in FIGS. 1-10, these referencecharacters in FIGS. 1l15, however, being primed. Thus, the chair shownin FIGS. l1-15 includes a vertical-frame part P having an upper sideframe part U'P supporting the arm A and an arm rest A'R'.

The compound hinge CH shown in FIGS. 11-15 differs from the compoundhinge CH described previously in that the compound hinge CH does nothave locating ears corresponding to the ears lb and 1c shown in FIGS.110. The hingestop part 1, however, does include a flat portion lahaving a stop ear Id providing a stop surface 1e. The hinge stop part Iis welded or otherwise secured to the vertical leg of an invertedL-shaped mounting piece 14, the top horizontal leg of which is welded orotherwise secured to the chair arm A.

The hinge component 2 is the same as the component 2 previouslydescribed and is mounted in the same manner, that is by a pivot screw3'. Also, the tablet T is secured to the second hinge component 8' andthe latter is pivotally mounted on the component 2, similarly to themounting described with reference to FIGS. 1-10.

The movements of the tablet T selectively to its three positions areeffected in the same manner as described with reference to FIGS. l10.However, the construction shown in FIGS. 11-15 includes an additionaldevice in the form of a tablet rest which locates the tablet accuratelyin a vertical plane when it is in its stowed position. As shown in FIG.15, a mounting bar 15 is secured to and extends forwardly from the framepart P. On each side of the mounting bar 15 is secured a socket member16 which receives a seat support 17 as shown most clearly in FIG. 12. Onone side of the mounting bar 15 and underneath the compound hinge CH ismounted a supporting plate 18 which carries a channel-shaped tablet rest19 which is open at its top and has spaced sides 20, 20 convergingtoward a root or seat 21. When the tablet T is swung from itsintermediate position to its stowed position, its leading edge passesbetween the tablet rest sides 20 which guide it into a vertical plane,the tablet edge then contacting and resting upon the root 21 of the rest19. The tablet rest 19 thus serves generally the same purpose as thespring 13 described with reference to FIGS. l--10 so that theconstruction shown in FIGS. 1l-15 need not include a correspondingspring, although such a spring may be employed to supplement the actionof the tablet rest 19 if desired.

The constructions illustrated and described embody the invention inpreferred forms, but it is intended that the disclosure be illustrativerather than definitive, the invention being defined in the claims.

I claim:

1. In a tablet chair structure including a chair frame, a chair seat, atablet, and means mounting said tablet on a side portion of said frameabove the level of said seat for movements to a use position over saidseat, to an intermediate position in which said tablet is in asubstantially vertical plane at said chair side and above said frameside portion, and to a stowed position below said frame side portion andalongside said frame in a substantially vertical plane extending foreand-aft of said chair, the improvement in that said mounting meanscomprises a hinge stop part on said frame side portion facing forwardlywith respect to said chair; a hinge component carried by said frame sideportion and mounted for pivotal movement about a first axis extendingtransversely to the fore-andaft line of the chair; and means mountingsaid tablet on said hinge component for pivotal movement about a secondaxis transverse to and offset from said first axis from a first positionin which said second axis extends fore-and-aft of said chair above saidfirst axis to a second position in which said second axis extendsfore-and-aft of said chair below said first axis, movement of saidtablet with said hinge component about said first axis from said stowedposition to said intermediate position with accompanying movement ofsaid second axis from its said second position to its said firstposition being limited by engagement of said hinge component with saidstop part.

2. Structure according to claim 1 in which said hinge stop partcomprises a flat portion secured to said frame side portion and lying ina plane extending fore-and-aft of the chair; and a stop ear projectingfrom said flat portion outwardly with respect to said chair.

3. Structure according to claim 1 in which movement of said tablet withsaid hinge component about said first axis from said intermediateposition to said stowed position with accompanying movement of saidsecond axis from its said first position to its said second position islimited by engagement of said hinge component with said hinge stop part.

4. Structure according to claim 2 in which said side portion of saidframe is a vertical member, and in which said hinge stop part comprisesan element having two locating ears spaced from each other fore-and-aftof the chair and projecting from said flat portion respectively in frontof and in rear of said vertical member and respectively engaging thefront and rear surfaces thereof, said stop ear projecting from said flatportion oppositely to said locating ears.

5. Structure according to claim 2 in which said side portion of saidframe is a substantially horizontal chair arm, said hinge stop partbeing mounted on said chair ann.

6. Structure according to claim 5 including an inverted L- i shapedmounting piece having 'one leg secured to the substantially horizontalsurface of said chair arm and having its other leg extending verticallyfrom said one leg, said hinge stop part being mounted on said other legof said mounting piece.

7. Structure according to claim 1 in which said tablet is offset fromsaid second axis transversely to said second axis, whereby when saidtablet is in-stowed position said tablet 'will tend to swing by gravityout of a vertical plane to assume an inclined position with its centerof gravity directly under said second axis, said structurefurtherinclndingspfing means interposed between said tablet and saidhinge component and being loaded when said=tablet is in stowed positionsufficiently to overcome the gravitational tendency of the tablet toswing to said inclined position and will thereby position said tabletsubstantially vertically.

8. Structure according to claim 1 further" including a tablet restsecured to the lower portion of said frame at the side thereof at whichsaid tablet is mounted,-said tablet rest being of channel shape facingupwardly andicomprising a root and two spaced upstanding sideshavingmu'tually diverging portions for receiving an edge portion of saidtablet as the latter is swung downwardly to stowed position, said sidesguiding said tablet to a substantially vertical position with its loweredge resting upon said root. 9. Structure according to claim 1 in whichsaid chair frame includes an arm over which said tablet extends when insaid use position, the means mounting said tablet on said hingecomponent comprising a second hinge component including a platelike partextending under said tablet and being secured thereto, said structurefurther includingasp'acer positioned against and secured to saidplatelike part and being restable upon said arm when said tablet is insaid useposition. 10. Structure according to claim 1 further includingfriction means for inhibiting swinging of said hinge component aboutsaid first axis. r

11. In a tablet chair structure including .a-chair frame, a chair seat,a tablet, and means mounting said tablet on a side portion of said frameabove the level of saidflseat for movements to a use position over saidseat, to an intermediate position in which said tablet is in asubstantially vertical plane at said chair side and above said frameside portion, and to a carried by said frame side portion and-mountedfor pivotal movement about a first axis extending transversely to theforeand-aft line of the chair; and means mounting said tablet on saidhinge component for pivotal movement about a second axis transverse toand offset from said first axis, said tablet being offset from saidsecond axis transversely to said second axis, whereby when said tabletis in stowed position alongside said frame said tablet will tend toswing by gravity out of said substantially vertical plane to assumea'position inclined with respect toand'out of saidsubstantiallyvei'tical plane with its center of gravity directly undersaid second axis, said structure further including spring meansinterposed between said tablet and said hinge component and being loadedwhen said tablet is in stowed position sufficiently to overcome thegravitational tendency of the tablet to swing to said inclined positionand will thereby position said tablet in said substantially verticallane. p 12. In a tablet chair structure including a chair frame, a chairseat, a tablet, and means mounting said tablet on a side portion of saidframe above the level of said seat for movements to a use position oversaid seat, to an intermediate position in which said tablet is in asubstantiallyvertical plane at said chair side and above said frame sideportion, and to a stowed position in a substantially vertical planebelow said frame side portion and alongside said frame, the improvementin that said mounting means comprises a hinge component carried by saidframe side portion and'mounted for pivotal movement about a firstaxisextending transverselyto the foreand-aft line of the chair; and meansmounting said tablet on said hinge component for pivotal movement abouta second axis transverse to and offset from said first axis, saidstructure further including a tablet rest secured to the lower portionof said frame at the side thereof at which said tablet is mounted, saidtablet restbeing of channel shape facing upwardly and comprising a rootand two spaced upstanding sides having mutually diverging portions forreceiving an edge-portion of said tablet as the latter is swungdownwardly tostowed position, said sides guiding said tablet to asubstantially vertical position with its lower edge resting upon saidroot.

